Abstract

We have examined the effect of thermally induced interdiffusion on the luminescence emission from red and infrared emitting self-assembled III–V quantum dots. Three different combinations of dot/barrier materials have been investigated: InAlAs/AlGaAs, InGaAs/AlGaAs and InGaAs/GaAs. In all cases, thermal intermixing was found to result in significant blueshifts of the photoluminescence(PL) emission. In addition, narrowing of the linewidth of the inhomogeneously broadened PL peak was observed. Both effects were found to be strongly dependent on the material system and average dot size. InAlAs/AlGaAs quantum dots exhibited the greatest linewidth reduction after intermixing, indicating this to be a promising method of achieving narrower luminescence lines for devices such as red-emitting zero-dimensional lasers.